Here is the full list of all 19 Sproggiwood achievements.
Kill 10 enemies in one turn.
Beat the Bloated Grotto on Savage with every class.
Beat a dungeon without killing any enemies besides the boss.
Beat Big Tree on Savage with every class.
Beat Goaturku on Savage with every class.
Beat Ickykolo on Savage with every class.
Defeat Surma on Normal.
Defeat Surma on Easy.
Kill a monster that loves you.
Kill 5 enemies in one turn.
Kill a bizarro cloghead.
Defeat Big Ick on Normal.
Defeat Big Ick on Easy.
Beat Hakkipunki on Savage with every class.
Beat Ignis Caverna on Savage with every class.
Beat Ensi on Savage with every class.
Beat the Floating Isles on Savage with every class.
Beat Uppmas Point on Savage with every class.
Beat the game on Savage with every class.